Plasma processing apparatus

Abstract

Provided is a technique capable of reducing a variation in processing in an in-plane direction of a sample and improving a yield of processing. A plasma processing apparatus 1 includes a first electrode (a base material 110B) disposed in a sample stage 110, a ring-shaped second electrode (a conductive ring 114) disposed surrounding an outer peripheral side of an upper surface portion 310 (a dielectric film portion 110A) of the sample stage 110, a dielectric ring-shaped member (a susceptor ring 113) that covers the second electrode and is disposed surrounding an outer periphery of the upper surface portion 310, a plurality of power supply paths that supply high frequency power from a high frequency power supply to the first electrode and the second electrode respectively, and a matching device 117 disposed on a power supply path to the second electrode. Further, a first position (A1) and a grounding position between the second electrode and the matching device 117 on the power supply path to the second electrode are electrically connected via a resistor 118 having a predetermined value.

The invention claimed is: 
     
       1. A plasma processing apparatus that processes a sample placed above an upper surface of a sample stage disposed in a processing chamber in a vacuum container using plasma generated in the sample chamber, the plasma processing apparatus comprising:
 a base material member including a convex portion on which the sample is placed, and having a first electrode disposed there-inside; 
 a ring-shaped second electrode disposed in a ring-shaped concave portion to surround the concave portion of the base material member on an outer peripheral side of the upper surface of the sample stage; 
 a dielectric ring-shaped member disposed in the concave portion to cover the second electrode and to surround an outer periphery of the concave portion of the base material member; 
 a plurality of power supply paths that supply high frequency power from a high frequency power supply to the first electrode and the second electrode respectively; and 
 a matching device disposed on a power supply path from the high frequency power supply to the second electrode out of the plurality of power supply paths and an impedance adjustable circuit disposed on the power supply path between the matching device and the second electrode, wherein a first position and a grounding position of the power supply path between the impedance adjustable circuit and the second electrode are electrically connected via only a resistive element, 
 wherein the ring-shaped second electrode is disposed inside the dielectric ring-shaped member. 
 
     
     
       2. The plasma processing apparatus according to  claim 1 , wherein
 base material member has a first diameter of the convex portion and a lower side portion that is below the concave portion having a second diameter larger than the first diameter, and 
 the ring-shaped member includes a first portion that covers the second electrode and is disposed on an outer peripheral side of the convex portion, and a second portion disposed on an outer peripheral side of the lower side portion. 
 
     
     
       3. The plasma processing apparatus according to  claim 1 , wherein
 the high frequency power supply includes a first high frequency power supply that is electrically connected to the first electrode and supplies first high frequency power of a first frequency to the first electrode and a second high frequency power supply that is electrically connected to the second electrode and supplies second high frequency power of a second frequency to the second electrode, 
 the plurality of power supply paths include a first power supply path that supplies the first high frequency power from the first high frequency power supply to the first electrode and a second power supply path that supplies the second high frequency power from the second high frequency power supply to the second electrode, and 
 the resistive element is provided between the first position and the grounding position on the second power supply path. 
 
     
     
       4. The plasma processing apparatus according to  claim 3 , wherein
 the second high frequency power is lower than the first high frequency power. 
 
     
     
       5. The plasma processing apparatus according to  claim 3 , wherein said first position is arranged at a predetermined position to provide a branch from the second power supply path to the grounding position of the second power supply path, and said resistive element has a predetermined value selected, to reduce a load impedance as seen from the first high frequency power supply so that said second high frequency power supplied by said second high frequency power supply can be set independently from said first high frequency power supply.